LocationExtAddress has not been found in the list of auto-initialized caches

Getting the below error in one of the customizations. Code Snippet below

Error: The entry form (ID: AR303000, title: Customers) cannot be automated. 
Failed to subscribe the event PX.Objects.AR.XXXExt::LocationExtAddress_CBranchID_CacheAttached in the graph PX.Objects.AR.CustomerMaint. 
The method signature looks like an event handler, but the cache LocationExtAddress has not been found in the list of auto-initialized caches. 
Remove unused event handlers from the code.

 public class XXXExt : PXGraphExtension<CustomerMaint.LocationDetailsExt, CustomerMaint.DefLocationExt, CustomerMaint.DefContactAddressExt,CustomerMaint>
    {

        protected virtual void LocationDetailsExt_CBranchID_CacheAttached(PXCache sender) { }

}